Introdução: Até o presente momento, há escassez de estudos que avaliem os níveis séricos de citocinas angiogênicas em pacientes com dermatomiosite (DM), uma miosite autoimune sistêmica que tem como fisiopatogênese a vasculopatia. Portanto, os objetivos do presente estudo foram: (a) analisar sistematica e simultaneamente os níveis séricos de angiogenin (ANG), angiopoietin (ANGPT) -1, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) -1 e -2 e platelet derived growth factor (PDGF) -AA e -BB em pacientes com DM; (b) correlacionar o nível sérico destas citocinas com as características clínico-laboratoriais, alterações metabólicas e atividade da DM. Pacientes e métodos: Estudo transversal, único centro, no qual foram incluídos, no período de 2012 a 2014, 48 pacientes consecutivos com DM definida (Bohan e Peter, 1975), entre 18 e 45 anos de idade, e em seguimento regular na nossa Instituição. Foram excluídos pacientes com condições clínicas relacionadas à DM (como sequelas de doença e tratamento prolongado) ou secundárias a outras causas que poderiam influenciar na interpretação dos resultados das citocinas avaliadas, seja por apresentarem variações hormonais ou por estarem relacionados ao mecanismo de inflamação e/ou angiogênese. Os pacientes foram pareados por sexo, idade e etnia com 48 indivíduos saudáveis (grupo controle). A análise das citocinas séricas foi realizada por imunoensaio multiplex. Os parâmetros da atividade da DM foram baseados nos escores estabelecidos por International Myositis Assessment & Clinical Studies Group (IMACS). Resultados: A distribuição de sexo e a etnia foram comparáveis entre os grupos DM e controle assim como a média de idade (33,3±7,6 vs. 35,8±8,2 anos, respectivamente), e a mediana de duração de doença foi de 1 ano. No grupo DM, os níveis séricos de FGF-1 e FGF-2 (P < 0,001, P < 0,001, respectivamente) estavam elevados, enquanto os níveis de VEGF e PDGF-AA (P=0,009 e P=0,022, respectivamente) estavam reduzidos. Os níveis de ANG, ANGPT-1 e PDGFBB foram semelhantes em ambos os grupos. Houve uma tendência para correlação positiva entre as citocinas (com exceção de VEGF e PDGF-BB) e os parâmetros de atividade da DM, enquanto FGF-2 apresentou correlação negativa. Além disso, o FGF-1 correlacionou-se fortemente com manifestações cutâneas da dermatomiosite. Conclusões: Os dados atuais reforçam a importância das citocinas angiogênicas nos mecanismos de vasculopatia da DM, especialmente em condições de atividade cutânea e adequado tratamento medicamentoso. Estudos adicionais serão necessários para validar os dados obtidos no presente trabalho / Introduction: Until now, there are few studies evaluating serum levels of angiogenic cytokines in patients with dermatomyositis (DM), a systemic autoimmune myositis that has vasculopathy as its physiopathogenesis. Therefore, the aims of the present study were: (a) to analyze systematically and simultaneously serum levels of angiogenin (ANG), angiopoietin (ANGPT) -1, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) -1 and -2, and platelet derived growth factor (PDGF) -AA and -BB in patients with DM; (b) to correlate the serum level of these cytokines with the clinical and laboratory features, metabolic alterations and DM activity. Patients and methods: This is an one-center cross sectional study, in which 48 consecutive patients with defined DM (Bohan and Peter, 1975) aged 18 to 45 years and regularly followed up at our Institution were included from 2012 to 2014. Patients with clinical conditions related to DM (as sequelae of disease and prolonged treatment) or secondary to other causes that could influence the results interpretation of the evaluated cytokines were excluded, either because of hormonal variations or relationship with inflammation mechanism and/or angiogenesis. Patients were gender-, age- and ethnicity-matched with 48 healthy individuals (control group). The serum levels of cytokines analyses were performed by multiplex immunoassay. The parameters of DM activity were based on the scores established by the International Myositis Assessment & Clinical Studies Group (IMACS). Results: The gender and ethnicity were comparable between DM and control groups as soon as the mean age (33.3±7.6 vs. 35.8±8.2 years, respectively), and the median disease duration was 1 year. The serum levels of FGF-1 and FGF-2 (P < 0.001 and P < 0.001, respectively) were higher in DM group, whereas the levels of VEGF and PDGF-AA (P=0.009 and P=0.022, respectively) were lower in DM group. The levels of ANG, ANGPT-1 and PDGF-BB were similar in both groups. There was a tendency for cytokines (with the exceptions of VEGF and PDGF-BB) to correlate positively with DM activity parameters, whereas FGF-2 correlated inversely. Moreover, FGF-1 strongly correlated with the cutaneous manifestations of DM. Conclusion: The current data reinforce the importance of angiogenic cytokines in DM vasculopathy mechanisms, especially in conditions of cutaneous activity and adequate drug treatment. Additional studies will be needed to validate the data obtained in this work

Objetivo: Avaliar os marcadores de reserva ovariana e anticorpos anti-corpo lúteo (anti-CoL) em pacientes com dermatomiosite (DM). Métodos: Todos as 40 pacientes do sexo feminino com DM, idade entre 18 e 42 anos, foram convidadas a participar. Os critérios de exclusão foram uso de contraceptivos hormonais nos últimos seis meses (n=13), associação de neoplasia (n=3), doenças autoimunes sistêmicas sobrepostas (n=3), gravidez atual (n=2), cirurgia ginecológica (n=1) e não concordância em participar do estudo (n=2). Dezesseis pacientes com DM e 23 controles saudáveis selecionados para participar deste estudo transversal foram avaliados na fase folicular precoce do ciclo menstrual. Anti-CoL IgG (immunoblotting), hormônio folículo estimulante (FSH), estradiol, inibina B, níveis séricos do hormônio anti-mülleriano (HAM) (ELISA) e contagem de folículos antrais (CFA) por ultrassonografia foram determinados. Resultados: Pacientes e controles tiveram média de idade, etnia e classe socioeconômica comparáveis (P > 0,05). A média de idade das pacientes foi de 29,1±4,7 anos e duração da doença de 5,6±3,2 anos. O ciclo menstrual, comorbidade e estilo de vida foram semelhantes em ambos os grupos (P > 0,05). HAM <= 1ng/mL (P=0,027) e número da CFA (P=0,017) foram significativamente reduzidos em pacientes com DM quando comparados ao grupo controle, enquanto que níveis séricos de estradiol (P < 0,001) foram maiores em pacientes com DM. Em contraste, os níveis de FSH no soro e inibina B, volumes de ovários, assim como a frequência de anticorpos anti-CoL foram semelhantes em ambos os grupos. Conclusão: O presente estudo foi o primeiro a identificar a reserva ovariana diminuída em pacientes com DM em idade reprodutiva. Mais estudos são necessários para avaliar os fatores envolvidos no prejuízo da reserva ovariana de pacientes com a miopatia inflamatória / Objectives: To assess ovarian reserve markers and anti-corpus luteum (anti-CoL) antibodies in dermatomyositis (DM) patients. Methods: All 40 female patients with DM, aged between 18 and 42 years, were invited to participate. Exclusion criteria were hormonal contraceptive use in the last six months (n=13), neoplasia associations (n=3), overlapped systemic autoimmune diseases (n=3), current pregnancy (n=2), gynecological surgery (n=1) and did not agree to participate of this study (n=2). Sixteen DM patients and 23 healthy controls were evaluated at early follicular phase of menstrual cycle were selected to participate in this cross-sectional study. IgG anti-CoL (immunoblotting), follicle stimulating hormone (FSH), estradiol, inhibin B, anti-müllerian hormone (AMH) serum levels (ELISA) and sonographicantral follicle count (AFC) was determined. Results: DM patients and controls had comparable mean age, ethnicity and socioeconomic class (P > 0.05). DM mean age of onset was 29.1±4.7 years and disease duration of 5.6±3.2 years. The menstrual cycles, comorbidity and life style were similar in both groups (P > 0.05). AMH<=1ng/mL (P=0.027) and number of the AFC (P=0.017) were significantly reduced in DM patients when compared to control groups, whereas serum estradiol level (P < 0.001) was higher in DM patients compared to controls. In contrast, serum FSH and inhibin B levels, ovarian volumes, as well as the frequency of anti-CoL antibody were alike in both groups. Conclusions: The present study was the first to identify diminished ovarian reserve in DM patients of reproductive age. Further studies are necessary to assess the idiopathic inflammatory myopathy-related factors involved in the ovarian impairment of patients

Objetivo: Avaliar os marcadores de reserva ovariana e anticorpos anti-corpo lúteo (anti-CoL) em pacientes com dermatomiosite (DM). Métodos: Todos as 40 pacientes do sexo feminino com DM, idade entre 18 e 42 anos, foram convidadas a participar. Os critérios de exclusão foram uso de contraceptivos hormonais nos últimos seis meses (n=13), associação de neoplasia (n=3), doenças autoimunes sistêmicas sobrepostas (n=3), gravidez atual (n=2), cirurgia ginecológica (n=1) e não concordância em participar do estudo (n=2). Dezesseis pacientes com DM e 23 controles saudáveis selecionados para participar deste estudo transversal foram avaliados na fase folicular precoce do ciclo menstrual. Anti-CoL IgG (immunoblotting), hormônio folículo estimulante (FSH), estradiol, inibina B, níveis séricos do hormônio anti-mülleriano (HAM) (ELISA) e contagem de folículos antrais (CFA) por ultrassonografia foram determinados. Resultados: Pacientes e controles tiveram média de idade, etnia e classe socioeconômica comparáveis (P > 0,05). A média de idade das pacientes foi de 29,1±4,7 anos e duração da doença de 5,6±3,2 anos. O ciclo menstrual, comorbidade e estilo de vida foram semelhantes em ambos os grupos (P > 0,05). HAM <= 1ng/mL (P=0,027) e número da CFA (P=0,017) foram significativamente reduzidos em pacientes com DM quando comparados ao grupo controle, enquanto que níveis séricos de estradiol (P < 0,001) foram maiores em pacientes com DM. Em contraste, os níveis de FSH no soro e inibina B, volumes de ovários, assim como a frequência de anticorpos anti-CoL foram semelhantes em ambos os grupos. Conclusão: O presente estudo foi o primeiro a identificar a reserva ovariana diminuída em pacientes com DM em idade reprodutiva. Mais estudos são necessários para avaliar os fatores envolvidos no prejuízo da reserva ovariana de pacientes com a miopatia inflamatória / Objectives: To assess ovarian reserve markers and anti-corpus luteum (anti-CoL) antibodies in dermatomyositis (DM) patients. Methods: All 40 female patients with DM, aged between 18 and 42 years, were invited to participate. Exclusion criteria were hormonal contraceptive use in the last six months (n=13), neoplasia associations (n=3), overlapped systemic autoimmune diseases (n=3), current pregnancy (n=2), gynecological surgery (n=1) and did not agree to participate of this study (n=2). Sixteen DM patients and 23 healthy controls were evaluated at early follicular phase of menstrual cycle were selected to participate in this cross-sectional study. IgG anti-CoL (immunoblotting), follicle stimulating hormone (FSH), estradiol, inhibin B, anti-müllerian hormone (AMH) serum levels (ELISA) and sonographicantral follicle count (AFC) was determined. Results: DM patients and controls had comparable mean age, ethnicity and socioeconomic class (P > 0.05). DM mean age of onset was 29.1±4.7 years and disease duration of 5.6±3.2 years. The menstrual cycles, comorbidity and life style were similar in both groups (P > 0.05). AMH<=1ng/mL (P=0.027) and number of the AFC (P=0.017) were significantly reduced in DM patients when compared to control groups, whereas serum estradiol level (P < 0.001) was higher in DM patients compared to controls. In contrast, serum FSH and inhibin B levels, ovarian volumes, as well as the frequency of anti-CoL antibody were alike in both groups. Conclusions: The present study was the first to identify diminished ovarian reserve in DM patients of reproductive age. Further studies are necessary to assess the idiopathic inflammatory myopathy-related factors involved in the ovarian impairment of patients

Introdução: Até o presente momento, há escassez de estudos que avaliem os níveis séricos de citocinas angiogênicas em pacientes com dermatomiosite (DM), uma miosite autoimune sistêmica que tem como fisiopatogênese a vasculopatia. Portanto, os objetivos do presente estudo foram: (a) analisar sistematica e simultaneamente os níveis séricos de angiogenin (ANG), angiopoietin (ANGPT) -1, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) -1 e -2 e platelet derived growth factor (PDGF) -AA e -BB em pacientes com DM; (b) correlacionar o nível sérico destas citocinas com as características clínico-laboratoriais, alterações metabólicas e atividade da DM. Pacientes e métodos: Estudo transversal, único centro, no qual foram incluídos, no período de 2012 a 2014, 48 pacientes consecutivos com DM definida (Bohan e Peter, 1975), entre 18 e 45 anos de idade, e em seguimento regular na nossa Instituição. Foram excluídos pacientes com condições clínicas relacionadas à DM (como sequelas de doença e tratamento prolongado) ou secundárias a outras causas que poderiam influenciar na interpretação dos resultados das citocinas avaliadas, seja por apresentarem variações hormonais ou por estarem relacionados ao mecanismo de inflamação e/ou angiogênese. Os pacientes foram pareados por sexo, idade e etnia com 48 indivíduos saudáveis (grupo controle). A análise das citocinas séricas foi realizada por imunoensaio multiplex. Os parâmetros da atividade da DM foram baseados nos escores estabelecidos por International Myositis Assessment & Clinical Studies Group (IMACS). Resultados: A distribuição de sexo e a etnia foram comparáveis entre os grupos DM e controle assim como a média de idade (33,3±7,6 vs. 35,8±8,2 anos, respectivamente), e a mediana de duração de doença foi de 1 ano. No grupo DM, os níveis séricos de FGF-1 e FGF-2 (P < 0,001, P < 0,001, respectivamente) estavam elevados, enquanto os níveis de VEGF e PDGF-AA (P=0,009 e P=0,022, respectivamente) estavam reduzidos. Os níveis de ANG, ANGPT-1 e PDGFBB foram semelhantes em ambos os grupos. Houve uma tendência para correlação positiva entre as citocinas (com exceção de VEGF e PDGF-BB) e os parâmetros de atividade da DM, enquanto FGF-2 apresentou correlação negativa. Além disso, o FGF-1 correlacionou-se fortemente com manifestações cutâneas da dermatomiosite. Conclusões: Os dados atuais reforçam a importância das citocinas angiogênicas nos mecanismos de vasculopatia da DM, especialmente em condições de atividade cutânea e adequado tratamento medicamentoso. Estudos adicionais serão necessários para validar os dados obtidos no presente trabalho / Introduction: Until now, there are few studies evaluating serum levels of angiogenic cytokines in patients with dermatomyositis (DM), a systemic autoimmune myositis that has vasculopathy as its physiopathogenesis. Therefore, the aims of the present study were: (a) to analyze systematically and simultaneously serum levels of angiogenin (ANG), angiopoietin (ANGPT) -1, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) -1 and -2, and platelet derived growth factor (PDGF) -AA and -BB in patients with DM; (b) to correlate the serum level of these cytokines with the clinical and laboratory features, metabolic alterations and DM activity. Patients and methods: This is an one-center cross sectional study, in which 48 consecutive patients with defined DM (Bohan and Peter, 1975) aged 18 to 45 years and regularly followed up at our Institution were included from 2012 to 2014. Patients with clinical conditions related to DM (as sequelae of disease and prolonged treatment) or secondary to other causes that could influence the results interpretation of the evaluated cytokines were excluded, either because of hormonal variations or relationship with inflammation mechanism and/or angiogenesis. Patients were gender-, age- and ethnicity-matched with 48 healthy individuals (control group). The serum levels of cytokines analyses were performed by multiplex immunoassay. The parameters of DM activity were based on the scores established by the International Myositis Assessment & Clinical Studies Group (IMACS). Results: The gender and ethnicity were comparable between DM and control groups as soon as the mean age (33.3±7.6 vs. 35.8±8.2 years, respectively), and the median disease duration was 1 year. The serum levels of FGF-1 and FGF-2 (P < 0.001 and P < 0.001, respectively) were higher in DM group, whereas the levels of VEGF and PDGF-AA (P=0.009 and P=0.022, respectively) were lower in DM group. The levels of ANG, ANGPT-1 and PDGF-BB were similar in both groups. There was a tendency for cytokines (with the exceptions of VEGF and PDGF-BB) to correlate positively with DM activity parameters, whereas FGF-2 correlated inversely. Moreover, FGF-1 strongly correlated with the cutaneous manifestations of DM. Conclusion: The current data reinforce the importance of angiogenic cytokines in DM vasculopathy mechanisms, especially in conditions of cutaneous activity and adequate drug treatment. Additional studies will be needed to validate the data obtained in this work

No description available.

Les myopathies inflammatoires idiopathiques (MII) sont hétérogènes dans leurs physiopathologies et pronostics. L'émergence d'auto-anticorps spécifiques de myosites (ASM) suggère des sous-groupes plus homogènes de patients. Notre but est de trouver une nouvelle classification des MII fondée des critères phénotypiques, biologiques et immunologiques. Une étude observationnelle, rétrospective, multicentrique a été conduite à partir de la base de données du réseau français des myosites. Nous avons inclus 260 myosites, définies selon les classifications historiques pour la polymyosite (PM), la dermatomyosite (DM) et la myosite à inclusions (MI). Tous les patients ont eu au moins un dot myosite testant les anti-Jo1, anti-PL7, anti-PL12, anti-Mi-2, anti-Ku, anti-PMScl, anti-Scl70 and anti-SRP. Nous avons utilisé l'analyse des correspondances multiples suivie d'une classification hiérarchique ascendante afin d'agréger les patients dans des sous-groupes plus homogènes. Quatre clusters émergent. Le premier cluster (n=77) regroupe principalement des MI, avec des vacuoles bordées, des anomalies mitochondriales et de l'inflammation avec des fibres envahies. Le second cluster (n=91) était caractérisé par des myopathies nécrosantes auto-immunes (MNAi) en majorité, avec des anticorps anti-SRP et anti-HMGCR. Le troisième cluster (n=52) regroupe essentiellement des DM avec des anticorps anti-Mi-2, anti-MDA5, ou anti-TiF1 gamma. Le quatrième cluster (n=40) était défini par le SAS (n=36), avec notamment la présence des anti-Jo1 ou anti-PL7. Les critères histologiques sont dispensables pour la prédiction des clusters, soulignant l'importance d'une classification clinico-sérologique. / Idiopathic inflammatory myopathies (IIM or myositis) are heterogeneous in their pathophysiology and prognosis. The emergence of myositis-specific autoantibodies (MSA) suggests homogenous subgroups of patients. Our aim was to find a new classification of IIM based on phenotypic, biological and immunological criteria. An observational, retrospective, multicentre study was led from the database of the myositis French network. We included 260 adult myositis, defined according to historical classifications for polymyositis (PM), dermatomyositis (DM) and inclusion body myositis (IBM). All patients did at least a screening with a line blot assays testing anti-Jo1, anti-PL7, anti-PL12, anti-Mi-2, anti-Ku, anti-PMScl, anti-Scl70 and anti-SRP. We performed multiple correspondence analysis and hierarchical clustering analysis to aggregate patients in homogenous subgroups. Four clusters emerged. The first cluster (n=77) regrouped primarily IBM patients with vacuolated fibres, mitochondrial abnormalities and inflammation with invaded fibres. The second cluster (n=91) was characterized by immune-mediated necrotizing myopathy (IMNM) in the majority of patients, with anti-SRP and anti-HMGCR antibodies. The third cluster (n=52) regrouped mainly DM patients with anti-Mi-2, anti-MDA5, or anti-TiF1 gamma antibodies. The fourth cluster (n=40) was defined by anti-synthetase syndrome (ASS), with the notable presence of anti-Jo1 or anti-PL7 antibodies. The histological criteria are dispensable for the prediction of the clusters, underlining the importance of a clinico-serological classification.

Nos últimos anos, os estudos de nosso grupo foram focados na área de dor, avaliando diferentes modelos experimentais de dor aguda, neuropática e muscular. A busca por mecanismos moduladores destes tipos de dores são alvo de grande estudo, uma vez que o fenômeno da dor é peculiar e torna-se de difícil tratamento em muitos casos. Distúrbios (VER) musculoesqueléticos são as principais causas de incapacidade nas pessoas durante seus anos de trabalho. Diversos estudos tem sido realizados lesionando o músculo gastrocnêmio como modelo experimental em diferentes animais para melhor entendimento deste tipo de dor. O nosso objetivo foi observar possíveis alterações histológicas no tecido muscular, avaliar a alteração na sensibilidade nociceptiva e a atividade locomotora dos animais após a indução de dor muscular crônica, bem como observar o envolvimento das células gliais na medula espinal destes animais. Em adição, avaliamos a participação de determinadas citocinas com o intuito de obter um perfil inflamatório em nosso modelo experimental. Nossos resultados demonstraram um quadro de inflamação instalada no tecido muscular de animais com miosite crônica através das analises histológicas realizadas. Os testes comportamentais tanto para hiperalgesia mecânica como térmica e alodinia confirmaram a instalação do quadro álgico uma vez que os animais com miosite apresentaram uma queda em seus limiares nociceptivos em relação aos grupos controle. A atividade locomotora dos animais também se demonstrou comprometida após a indução de miosite. Em relação à participação das células gliais neste modelo, demonstramos que houve um aumento na expressão de GFAP e OX-42, correspondentes à marcação astrócitos e células da microglia na porção lombar da medula espinal dos animais com miosite, quando comparados ao grupo controle. Quanto à participação dos mediadores sistêmicos, observamos um aumento nos níveis de IL-1&#946; e fractalquina (FKN) no sangue dos animais, enquanto o nível de IL-10 permaneceu baixo em relação ao grupo controle. Com nossos achados esperamos colaborar com o aprimoramento de estratégias terapêuticas para tratamento de dores musculares. / In the last years, the studies of our group were focused on the area of pain, evaluating different experimental models of acute, neuropathic and muscular pain. The search for mechanisms modulating types of pain are the subject of great study, since the phenomenon of pain is peculiar and becomes difficult in many cases. Musculoskeletal (VER) disorders are the leading causes of disability in people during their working years. Several studies have been carried out with the model of experimental model in different animals to better understand this type of pain. Our objective was to observe the non-muscular histological changes, to evaluate the nociceptive sensitivity and a locomotor activity of the animals after an induction of chronic muscular pain, as well as to observe the involvement of the glial cells in the spinal cord of the animals. In addition, we evaluated the participation of certain cytokines in order to obtain an inflammatory profile in our experimental model. Our results demonstrated a picture of inflammation installed without muscle tissue of animals with chronic myositis through histological analysis. Behavioral tests for both mechanical and thermal hyperalgesia and allodynia confirmed the onset of pain since animals with myositis showed a decrease in their nociceptive thresholds in relation to the control groups. The locomotor activity of the animals was also shown to be impaired after an induction of myositis. Regarding the participation of glial cells in this model, we demonstrated that there was an increase in the expression of GFAP and OX-42, corresponding to marking astrocytes and microglia cells in the portion of the spinal cord of animals with myositis, when compared to the control group. Regarding the participation of systemic mediators, we observed an increase in the levels of IL-1&#946; and fractalkin (FKN) in the blood of the animals, while the level of IL-10 remained low in relation to the control group. With the findings we hope to collaborate with the improvement of therapeutic strategies for the treatment of muscular pain.

Les myopathies auto-immunes (MAI), classiquement appelées myosites ou myopathies inflammatoires idiopathiques, représentent un groupe de maladies définies par des caractéristiques cliniques, histopathologiques et biologiques. Une des caractéristiques les plus notables est la présence d’auto-anticorps (aAc) chez environ 60% des patients. Les MAI regroupent : les dermatomyosites, les polymyosites, les myosites à inclusion, les myosites de chevauchement incluant le syndrome des anti-synthétases et les myopathies nécrosantes auto-immunes (MNAI). Les MNAI ont été récemment individualisées parmi les MAI comme des maladies graves fréquemment associées à la présence d’aAc dirigés contre la Signal Recognition Particle (SRP) ou la 3-Hydroxy-3-MéthylGlutaryl-CoA Réductase (HMGCR). La localisation de SRP et HMGCR étant intracellulaire, le rôle des aAc dans la physiopathologie des MNAI reste mal compris. La pathogénicité des aAc anti-SRP et anti-HMGCR envers des cellules musculaires cultivées in vitro a récemment été mise en évidence mais leurs effets in vivo demeurent inconnus.Au cours de cette thèse, j’ai étudié le rôle physiopathologique des aAc anti-SRP et anti-HMGCR in vivo chez la souris. Le transfert passif d’IgG de patients atteints de MNAI, positifs pour les aAc anti-SRP ou anti-HMGCR, à la souris sauvage entraîne un déficit musculaire. Ce déficit était prolongé chez la souris immunodéficiente Rag2-/-, et limité chez la souris déficiente pour la fraction C3 du complément. Chez les souris recevant les IgG anti-SRP+, le déficit musculaire était important et accompagné de quelques signes de nécrose myocytaire. Les IgG anti-HMGCR+ induisaient une faiblesse musculaire moindre, et des signes histopathologiques rares ou absents. Ces résultats sont en accord avec l’observation chez l’homme d’une maladie plus grave chez les patients anti-SRP+ par rapport aux patients anti-HMGCR+. La supplémentation en complément humain des souris augmentait le déficit musculaire induit par les IgG anti-HMGCR+ et de façon moindre pour les IgG anti-SRP+. En collaboration avec l’INSERM UMRS974, nous avons montré que les cibles SRP et HMGCR peuvent être détectées à la surface des fibres musculaires in vitro, suggérant qu’elles puissent être accessibles aux aAc in vivo.Ces résultats démontrent pour la première fois le rôle pathogène des aAc anti-SRP et anti-HMGCR in vivo et l’implication du complément, contribuant à une avancée dans la compréhension de la physiopathologie des MNAI. / Autoimmune myopathies (AIM), classically called myositis or idiopathic inflammatory myopathies, represent a group of diseases characterized by clinical, histopathologic and biologic properties. One of the most notable properties is the presence of autoantibodies (aAb) in approximately 60% of patients. AIM includes five principal entities: dermatomyositis, polymyositis, inclusion body myositis, overlap myositis including the anti-synthetase syndrome and immune-mediated necrotizing myopathies (IMNM). IMNM have recently been individualized among AIM as severe diseases frequently associated with aAb directed against Signal Recognition Particle (SRP) or 3-Hydroxy-3-MethylGlutaryl-CoA Reductase (HMGCR). Since SRP and HMGCR have an intracellular localization, the role of anti-SRP and anti-HMGCR aAb in the pathophysiology of IMNM remains unclear. Anti-SRP and anti-HMGCR aAb were recently shown to be pathogenic to muscle cells in vitro but in vivo effects remain unknown.During this thesis, I studied the pathophysiological role of anti-SRP and anti-HMGCR aAb in vivo in mice. Passive transfer of IgG purified from plasma of IMNM patients positive for anti-SRP and anti-HMGCR aAb to wild-type mice elicited a muscle weakness. Immune-deficient Rag2-/- mice presented a prolonged muscle deficit, whereas complement component C3 deficient mice had limited signs. Mice injected with anti-SRP+ IgG displayed a strong muscle weakness with mild myocytic necrosis. The muscle deficit was milder and histopathologic findings were not always present in mice receiving anti-HMGCR+ IgG. This is in accordance with clinical findings in anti-SRP+ patients which present a more severe disease than anti-HMGCR+ patients. When supplemented with human complement, mice receiving anti-HMGCR+ IgG showed a more severe muscle deficit. This supplementation increased the deficit induced by anti-SRP IgG in a milder way. In collaboration with INSERM UMRS974, we showed that the targets SRP and HMGCR can be detected on the surface of myofibres in vitro, suggesting that they could be accessible to aAb in vivo.Together, these results demonstrate for the first time the pathogenic role of anti-SRP and anti-HMGCR aAb in vivo and the implication of complement, contributing to a progress in the comprehension of MNAI pathophysiology.

In this project, the effects of dietary polyphenols on exercise-induced muscle damage and vascular health are examined. Dietary polyphenols exert well-known anti-inflammatory effects; however, how these effects are realized with respect to vascular health and EIMD is relatively unknown. I begin by reviewing the available literature surrounding the impact of three dietary polyphenols (curcumin, catechins, and quercetin) on inflammation associated with EIMD. It is well established that their primary means of anti-inflammation is through alterations of NF-κB and AP-1 transcription activities. Given this, their inclusion into training strategies seems reasonable. Consistent evidence is presented making a case for the anti-inflammatory effects of dietary polyphenols following EIMD. I follow this review up by completing an in-depth study on the consumption of curcumin prior to EIMD. I found curcumin (1000 mg/day) can reduce subjective soreness and decrease inflammation compared to placebo controls. To further understand the effects of dietary polyphenols on health, I investigate the effects of a four-week supplementation period of cocoa (catechins) on vascular. I concluded that atherogenic risk in obese women is reduced after consumption of cocoa. In addition to these experimental projects, I developed two novel methods that can be used to investigate vascular health (EMP concentration) and intracellular protein and mRNA production using flow cytometry.

Introdução: As estatinas são drogas amplamente utilizadas na prevenção primária e secundária de doenças cardiovasculares, por reduzirem o nível de colesterol. Porém alguns pacientes podem apresentar elevação da creatinofosfoquinase (CPK) e sintomas musculares relacionados ao seu uso. Além da CPK, outros marcadores de dano muscular podem apresentar alterações. Este estudo analisou a concentração dos marcadores bioquímicos, CKMB e anidrase carbônica III (CAIII) e sua relação com a presença de miosite. Métodos: Foram selecionados pacientes em tratamento com estatinas e com elevação da CPK. Foram realizadas as determinações de CKMB e CAIII e analisadas as variáveis clínicas e laboratoriais destes pacientes. Resultados: Cerca de 10% dos pacientes em tratamento com estatina apresentaram elevações de CPK acima 1x o limite superior de normalidade (LSN). Desses, 50,4% apresentaram sintomas musculares, definido como miosite. O uso de sinvastatina [OR=2,24 (IC95%:1,47-3,42)], o índice de massa corpórea > 28 Kg/m2 [OR=1,06 (IC95%: 1,01-1,10)] e a CKMB > 1xLSN [OR=1,59 (IC95%: 1,02-2,49)] apresentaram-se como preditores independentes para a ocorrência de miosite. A CKMB aumentada foi observada em 36,2% dos pacientes (7,17±4,4 ng/mL). Os pacientes com e sem miosite apresentaram valores semelhantes de CAIII (211,3±93,4pg/mL vs 204,0±84,6pg/mL; p=0,549). Pacientes diabéticos apresentaram elevações significantes de CKMB em relação aos não diabéticos (4,8±4,6ng/mL vs 3,5±2,4ng/mL; p=0,0006) e não apresentaram diferenças quanto à presença de miosite. Conclusão: A CKMB apresentou alteração em parte dos pacientes tratados com estatinas e foi um preditor independente para a presença de miosite. A CAIII não foi considerada um bom marcador de dano muscular na população deste estudo / Introduction: Statins are drugs widely used in primary and secondary prevention of cardiovascular diseases, due to the decreasing effect on cholesterol level. However, some patients may present elevated levels of creatine phosphokinase (CK) and muscle symptoms related to statin use. In addition to CK, other markers of muscle damage may present changes. This study analyzed the concentration of biochemical markers, CKMB and carbonic anhydrase III (CAIII) and related them to the presence of myositis. Methods: Patients on statin therapy and CK elevation were selected. CKMB and (CAIII) assays were performed and the clinical and laboratory variables of these patients were analyzed. Results: About 10% of the patients receiving statin therapy (6692) presented CK elevations above 1x upper reference limit (URL). Muscular symptoms, defined as myositis, were presented in 50.4% of these patients. Use of simvastatin [OR=2,24 (IC95%:1,47-3,42)], a body mass index > 28 kg / m2 [OR = 1.06 (95% CI: 1.01-1, 10)] and a concentration of CKMB > 1x URL [OR = 1.59 (95% CI: 1.02-2.49)] presented as independent predictors for the occurrence of myositis. Increased CKMB was observed in 36.2% of patients (7.17 ± 4.4 ng / mL). Patients with and without myositis had similar CAIII values (211.3 ± 93.4pg / mL vs 204.0 ± 84.6pg / mL, p = 0.549). Diabetic patients showed significant elevations of CKMB compared to non-diabetic patients (4.8 ± 4.6 ng / mL vs. 3.5 ± 2.4 ng / mL, p = 0.0006) and did not present differences regarding the presence of myositis. Conclusion: CKMB level changed in part of the patients treated with statins and this enzyme was an independent predictor for the presence of myositis. CAIII was not considered a good marker of muscle damage in the studied population